Updated LinuxBridge plugin to be able to retrieve address informations

[gabrik]

Updated the LinuxBridge plugin, now it is able looking at dnsmasq lease files to get information about ip addresses of a FDU.
LXD Plugin is already using this feature to retrieve network information about LXD containers.
This infomation can be retrieved using api.fdu.instance_info(<instance uuid>)

The return is a JSON like this:

{
   "fdu_uuid":"1e57bb0e-cb41-4b23-bca3-1fa761a83c02",
   "node":"a2d358aa-af2b-42cb-8d23-a89e88b97e5c",
   "uuid":"def296eb-558c-4cba-b35e-78774281e3be",
   "status":"RUN",
   "interfaces":[
      {
         "vintf_name":"eth0",
         "status":"CREATE",
         "if_type":"VIRTIO",
         "mac_address":"be:ef:be:ef:00:01",
         "cp_id":"2124768b-8304-420a-b6f6-4740cb12caf4"
      }
   ],
   "connection_points":[
      {
         "uuid":"2124768b-8304-420a-b6f6-4740cb12caf4",
         "status":"CREATE",
         "cp_uuid":"a47a8819-72e5-4b4e-86fd-fc30c9fda68b"
      }
   ],
   "hypervisor_info":{
      "network":[
         {
            "name":"eth0",
            "mac_address":"be:ef:be:ef:00:01",
            "address":"192.168.234.10"
         }
      ],
      "cpu":{
         "usage":1705533730
      },
      "memory":{
         "usage":3321856,
         "usage_peak":8728576,
         "swap_usage":0,
         "swap_usage_peak":0
      },
      "disk":{
         "root":{
            "usage":108544
         }
      },
      "processes":5,
      "pid":8895
   },
   "accelerators":{
      "fpga":[

      ],
      "gpu":[

      ]
   },
   "io_ports":[

   ]
}

This will help in #96